IWBs & Dimmers... Combined

[TomHoward]

As long as the MCB is next to the corresponding socket (as opposed to at the other end of the bar) I don't see a huge advantage of being able to reset remotely. (Unless you're attaching multiple lamps to a single socket and you'd hope to continue the gig a lamp down). In most situations you'd have to visit the fixture to change the lamp anyway, so if it was within reach you could reset it.

[dmxtothemax]

So fuses dont go!

I wish!

If you run your dimmers at full output, or near to full output,

They do indead go, you see even fuses have a finite life span,

Even with the best quality fuses,

I got so annoyed by the no reason blowing of fuses,

I replaced them with circuit breakers.

I think that at high current, just the tinyest resistance causes heat and subsiquent failure.

 

However, fuses/trips don't just go in my experience. I've only taken a fuse/mcb out with a lamp blowing, or a very few well aged fuses with unrush current, but MCBs don't really suffer from that.

 

If you've got to go up to change the lamp then you can reset the trip while you're there (assuming sensible product design that puts the MCB near the outlet).

[matt_beal]

It's much more of a problem if you are running the dimmer (as a whole) at or near full capacity when the lamp goes as you could take out the incoming MCB. If this is built into the dimmer/bar, it is much more of an issue as you will immediately lose any other lights you have on that dimmer.

 

On a small show, this might just make it neccessary for a mid-show reset and if it's at height it's not going to be easy...

[dbuckley]

Again, these concerns are only relevant with SCR based bars - IGBT bars dont have fuses or breakers per channel, and if a channel shorts it isn't going to pop the main breaker, whether it is on the bar or in a closet.

[musht]

IES were the Dutch company bought by ETC

 

IGBT dimming could mean sine wave dimming and/or reverse phase control.

 

RPC has a downside, it won`t dim inductive loads, trafo fed birdies and things are liable to kill dimmer, sine wave can control just about anything becasue voltage can be limited on output, internally very complex dimmer though.

 

http://livedesignonline.com/mag/lighting_s..._new/index.html

[Tomo]

Actually, the IES IGBT reverse/forward phase dimmers were discontinued a few years ago.

IGBT RPC has a lot of limitations and is not very efficient, as musht mentioned - it's only really suitable for low-current (maybe 10A) dimming of tungsten and ballasts/electronic transformers specifically requiring that kind of control.

 

Sinewave is considerably better for a similar cost - particularly as it'll control almost any load.

 

It should be noted that both IES IGBT and IES by ETC Sinewave dimmers do contain fuses/MCBs - it's just that they're much less likely to blow/trip as the electronic protection will usually catch any shorts before the fuse blows.

[lampycakes]

I was a PSL last week and Philips Strand have launched a IGBT 6 lamp bar, but are also selling the componants so you can make your own bars.

[GregB]

How lovely to see such a balanced view on remote/distributed dimming. There are many obvious (and not so obvious) advantages to distributed dimming. The greatest herdle I have encountered is 'proffessional opinion'!

Dimming is where it is now because YOU cant be persuaded to distribute your dimming and run mains instead of multicore.

With wireless DMX comming of age surely there are even more reasons now to make the change.

Main distribution and DMX over wieless (even with cabled back up for THAT really important show is cheaper, easier and quicker then our usual system.

 

rattaatttattt sound of gun fire follows :D

 

Mathew, If you have an idea research it, follow it up, you never know what you might have!

[david.elsbury]

Dimming is where it is now because YOU cant be persuaded to distribute your dimming and run mains instead of multicore.

I disagree... dimming is where it is because most venues have already been built to handle a centralised dimmer system, with cable sized at perhaps 10A per channel. To retrofit it with DMX waylines, splitters and heavy enough cabling to handle 30A feeds at the lighting bars for distributed dimming may not be feasible.

 

However, a brand new venue is a different story, as is a retrofit.

[GregB]

"is where it is because most venues have already been built to handle a centralised dimmer system" Not true. Mainly old style theatre have this issue. Most venues I've visited/worked always have plenty fo power supply on/near to stage.

Most venues and events now require distributed mains in the grid to run LED and movers. Its really not an argument.

[Ynot]

"is where it is because most venues have already been built to handle a centralised dimmer system" Not true. Mainly old style theatre have this issue. Most venues I've visited/worked always have plenty fo power supply on/near to stage.

Most venues and events now require distributed mains in the grid to run LED and movers. Its really not an argument.

Hmmmm....

How many venues have you worked where the dimming is actually in the grid? ie on the bars themselves?

The key point that was mentioned very early on in this topic was that of resetting trips/breakers - Whilst it was said that if you're up a ladder/talle to replace a lamp you'd be in the position of resetting a trip, and that obviously would need to be in the interval/post show. BUT if you're running 2 or more lanterns on a circuit where one lamp blows, taking out the breaker, with a centralised dimmer system at least then you can at least get other lanterns on that circuit back on line immediately.

[Matthew Robinson]

"is where it is because most venues have already been built to handle a centralised dimmer system" Not true. Mainly old style theatre have this issue. Most venues I've visited/worked always have plenty fo power supply on/near to stage.

Most venues and events now require distributed mains in the grid to run LED and movers. Its really not an argument.

Hmmmm....

How many venues have you worked where the dimming is actually in the grid? ie on the bars themselves?

The key point that was mentioned very early on in this topic was that of resetting trips/breakers - Whilst it was said that if you're up a ladder/talle to replace a lamp you'd be in the position of resetting a trip, and that obviously would need to be in the interval/post show. BUT if you're running 2 or more lanterns on a circuit where one lamp blows, taking out the breaker, with a centralised dimmer system at least then you can at least get other lanterns on that circuit back on line immediately.

 

What about if you could reset breakers remotely?

[AndyJones]

That would be dangerous, If you have tripped it out so that you can do some work on the channel, you don't want people to be able to remotely trip it back in.

[Andrew C]

I agree, even though the first thing that anyone does with a tripped beaker is to reset it to see if it goes again. Only then do you start looking for a real fault. You would need a "proper" means of isolation as well.

[dbuckley]

What about if you could reset breakers remotely?

Or, as noted above, there were no breakers to trip?